But where will Facebook's legal protection be without the second half of that name — the all-important and well-beloved word "book"?

Amusingly, the trademark rights to "book" have already been applied for by an obscure North Carolina corporation called myEworkBook Inc., which filed for it in October. Though the company's myeworkbook.com is a non-functional website, its business is described in the trademark file as "an online community for registered users to participate in discussions, get feedback from their peers, form virtual communities, and engage in social networking featuring educational purposes."

The application is marked as pending and has not yet been been assigned to an examining attorney -- meaning it may or may not be approved.

The firm, as described, is in the same general realm as Facebook, also an online social networking site. The more similarities in the services that two companies provide, the better chance for the owner of a trademark to prevent a second company from using it.

As you can see from myEworkBook's trademarked image mark above right, their mark bears some basic resemblance to Facebook's — which may perhaps slow down the social networking giant from grabbing the tail end of its name, assuming it got beaten out by the upstart web site.

Facebook and the owner of myEworkBook did not immediately respond to questions about the book mark.

Corrected at 4:27 p.m. to reflect that myEworkBook's application has been pending since early October, and has not yet been assigned to a Patent Office attorney, or approved.

— David Sarno

Image: An illustration from the U.S. Patent Office web site featuring myEworkBook's trademark.